The present invention relates to a gas lock for separating two gas chambers, which while taking up minimal space makes it possible to achieve the separation of gases without contact with the product/educt/transporting system. The gas lock according to the invention is distinguished by the integration of a measuring chamber for measuring at least one physical and/or chemical property. Also, the present invention relates to a coating device which comprises a gas lock according to the invention. Also provided are possibilities for using the gas lock according to the invention.
To reduce costs, coating plants are designed with the aim of creating continuous educt and product flows. In many fields, however, the separation of the process gases in the plant and the separation of the environment from the process gases represent a problem.
In the case of continuous plants, which have to dispense with conventional sealing concepts, essentially the following difficulties arise:    a) Intermixing of gases from different process steps has to be precluded since this would render the product unusable (for example the layer structure may be significantly influenced and the product destroyed).    b) The mostly toxic and/or explosive process gases have to be reliably separated from the environment in order to avoid safety risks (poisoning and explosions).    c) The separation of the gases has to be detectable without having to measure the pressure in toxic and/or explosive gases. A failure of the sealing concept can therefore be detected before the process gases are intermixed or flow out of the plant (interruptions in the process destroy the product, and explosion-proof devices represent an enormous cost factor in plant construction and are avoided).    d) The concept has to be kept spatially compact in order to design the plants in an economical manner.    e) The concept must not generate any wear so as to keep the up-time of the plant as high as possible and so as not to damage the products (no mechanical contact with the transporting system or with the product).
Up to now, the aforesaid set of problems has been solved by conventional sealing of the gas chambers by using gastight chambers (by means of mechanical seals). This, however, leads to the transporting system not being able to function continuously and to there being the risk of wear or damage (see point e)).
Another possibility is the use of gas sprays. In this case, however, there is the problem that in the currently standard forms these are too undirected and do not create sufficiently tolerant and economical gas separation for high-purity processes. This leads to the aforesaid problems a), b) and c) and to lower up-time of the plant.